1. Field of the Invention
The present invention relates generally to an image capturing apparatus and method for use in an image in a mobile terminal, and in particular, an image capturing apparatus and method for minimizing a display stop time generated during image capturing.
2. Description of the Related Art
In recent years, most mobile terminals tend to basically have a digital camera function that can capture an image at a high pixel resolution, for example, a five-mega pixel resolution or higher. Digital cameras built in the mobile terminals take a photograph using a preview operation and an image capturing process. The preview operation is a process of displaying an image inputted through a camera sensor on an external display device, and the image capturing process is a process of capturing a specific still image. In order to minimize the processing speed delay caused by an increase in an amount of data when capturing an image at a high pixel resolution, most digital cameras display frames at high speed by reducing the amount of data using an auxiliary method during the preview operation. Examples of the auxiliary method include a sub-sampling method, an omitting method, and a windowing method. The sub-sampling method is to output all frames of the image signals input through the camera sensor by reducing a vertical resolution of the image signals. The omitting method is for outputting the image signals by omitting a predetermined number of frames at regular intervals. The windowing method is for outputting only the image signals corresponding to a specific portion of the frame. Upon selection of an image capture key, an entire amount of the data is received and an image capture process is performed for capturing the corresponding image.
FIG. 1 is a flowchart diagram illustrating an image capturing process of a conventional mobile terminal. An example of the image capturing process is where the sub-sampling method is used during the preview operation.
Referring to FIG. 1, during the preview operation when a capture of a still image is selected using the sub-sampling method (101), the preview operation is stopped (103) and the sub-sampling is released (105). Then, an image capture process is performed to capture a specific still image inputted through a camera sensor (107), and the image capture is done after a predetermined time (109).
In order to stop the preview operation, a data processing time indicated by “a” period 120 is required. In order to release and stabilize the sub-sampling, a data processing time indicated by “b” period 122 is required. The data processing time increases in proportion to the pixel resolution. In the case of 2-3 mega pixel resolution, more than five seconds are required for the data processing.
The preview operation is stopped during the data processing time (i.e., “a” period+“b” period), so that the image signal inputted through the camera sensor is not displayed on the external display device. The conventional mobile terminal displays one of a stopped image during the preview operation stop time, and another image so as to hide the stopped image. In this case, a user has to wait until an image is captured, while viewing the stopped display image or the specific image during the preview stop time that is proportional to the pixel resolution. If the mobile terminal moves immediately after the user issues a capture command, that is, before the image is captured after the preview is stopped, the stopped preview image is quite different from an actually captured image.